Clean-out block assembly



June 24, 1941. H. L, SMALLEY CLEAN-OUT BLOCK ASSEMBLY Filed May 1, 1940 4 IIVgYENTOR. 2%

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Patented .Fune 24, 194i 'r'rss CLEAN-GUT BLOCK ASSEli/ELY Application May 1, 1940, Serial No. 322,759

5 Claims.

This invention relates to refractory furnace walls provided with clean-out openings, and more particularly to a structure by which those openings are formed and are sealed when not in use.

The refractory walls of certain types of furnaces, regenerators for example, are provided at intervals with normally closed openings through which suitable implements may be inserted to lance or clean the furnace. Between cleaning periods these openings should be tightly sealed to prevent the escape of heat therefrom and infiltration of air, and, in the case of regenerators, to prevent the escape of the air blast that is forced through the regenerators under high pressure. Heretofore it has been customary to close the clean-out openings with plugs that are luted into place with fire clay. This time consuming method has always been unsatisfactory because it is difficult to provide a seal and the discarded clay is rather dirty and disagreeable to handle, and

because the plug may jar loose.

It is among the objects of this invention to provide relatively simple and inexpensive means forming a normally sealed clean-out opening which can be readily opened or closed and in which the seal is complete and dependable.

In accordance with this invention a block, which takes the place of one or more of the ordinary bricks that form the side wall of the furnace, is provided with apassage therethrough in which there is an outwardly facing shoulder. This passage normally is closed by a plug inserted therein and having a surface facing the shoulder. The shoulder-facing surface of the plug may be formed by enlarging the outer end portion of the plug to produce a plug shoulder. The plug shoulder is biased toward the block shoulder by means connected to the block and plug, and resilient sealing means is compressed between the two shoulders so that no hot gases can escape nor cold air infiltrate between the plug and block. The inner end portion of the plug may be provided with heat insulating material to decrease the flow of heat through the plug to the sealing means. The plug is preferably provided with means for preventing it from being rotated against the sealing means which it might otherwise abrade.

The preferred embodiment of the invention is illustrated in the accompanying drawing in which Fig. 1 is a fragmentary perspective view of a regenerator showing some of the clean-out openings; Fig. 2 is an enlarged longitudinal view of half of a clean-out block with a sealing plug therein; Fig. 3 is an outer end View of the block assembly; and Fig. 4 is a longitudinal view of half of the clean-out block assembly with a modified type of block at its inner end.

Referring to Fig. l of the drawing, a furnace wall l is provided with a plurality of clean-out openings or passages 2 extending therethrough. Each opening is formed by a pair of refractory blocks through which axially aligned passages 2 extend, although with thinner walls only the outer block is used. To facilitate forming these passages each block is preferably composed of two substantially identical bricks 3 in each of which half of the passage is formed. The two bricks, which are laid together as in Fig. 3, will be treated herein as a single block. In accordance with this invention, each passage 2' has its outer end portion enlarged to form an outwardly facing shoulder l, as shown in Fig. 2. The passage is normally closed by a plug 6 that has a reduced inner end which fits loosely in the reduced end of the passage and an enlarged outer end that is disposed in the enlarged end of the passage and which forms with the reduced portiondof the plug a radial shoulder l facing shoulder To seal the space between the plug and passage wall so that hot gases cannot escape from the furnace nor cold air infiltrate, passage shoulder l is provided with an annular groove in which a resilient sealing member 8 is mounted. This sealing member should be capable of withstanding high temperatures, a ring of asbestos ropebeing suitable for this purpose. The plug is pressed against the sealing member, so that it will be compressed between the shoulders 4 and l andthereby effectively seal the space between them, by means connected to the block. Preferably, this means consists of an inwardly bowed steel spring strip 9 whose outer ends are held by the block and whose center portion bears against the end of the plug or against handle I I extending transversely of the outer end of the plug to which it is integrally connected.

To permit the spring to be readily mounted in operative position and removed therefrom, the wall of the enlarged portion of passage 2 is provided with a pair of oppositely disposed recesses 12 that extend inwardly along the passage from its outer end. This wall is also provided with a pair of oppositely disposed grooves l 3 that extend circumferentially around the passage from the two recesses. Spring 9 is longer than the diameter of the enlarged end of the passage, but short enough to permit its opposite ends to be inserted in recesses I 2 and moved inwardly of the passage therein. When the ends of the spring reach grooves l3, following engagement of its central portion with the plug, it is rotated in a vertical plane to cause its ends to enter and slide along the grooves, thus connecting the spring to the block and biasing the plug inwardly.

As the rotation of the spring into place in grooves l3 might turn the plug a little, which would cause its shoulder 1 to rotate against the sealing member and abrade it, the plug is provided with means for preventing its rotation. This means most conveniently takes the form of a pair of laterally projecting bosses [4 that extend into the two recesses E2 in the wall of the passage. The recesses are extended inwardly substantially to the passage shoulder 4, and the bosses are elongated axially of the plug. This construction not only prevents the plug from rotating, but it also centers it in the passage and causes it to bear with substantially equal force upon both the upper and lower portion of the sealing member.

In case it is feared that so much heat may be conducted to sealing member 8 that it will be disintegrated due to dehydration, the inner end portion of the plug can be made hollow and then filled with heat insulating concrete IE or the like sealed in by a high temperature cement layer [1.

In case there is a tendency for the lancing tool to catch on the inner block when it is being withdrawn from the furnace, the type of inner block l8 shown in Fig. 4 can be used. The passage I9 through this block flares outwardly at its inner end so that a smooth and continuous surface is formed free of shoulders or other obstructions. With either of the embodiments disclosed herein, a filler block 20 can be used if the wall is thicker than two of the clean-out blocks.

A clean-out block assembly of the character disclosed herein is highly effective for its purpose despite its simplicity. The plug is held positively in place by means that will not jar loose but which can quickly be removed and replaced when it is desired to open the clean-out passage to permit the furnace to be lanced. The compressible seal between the plug and block shoulders forms an excellent seal and eliminates the necessity for luting.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiments. However, I desire to have itunderstood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A clean-out block assembly for use in a furnace wall, comprising a block provided with a passage therethrough having an enlarged outer end to form an outwardly facing shoulder, a plug disposed in said passage and having an enlarged outer end portion disposed in the enlarged end of the passage forming an inwardly facing shoulder opposite said passage shoulder, sealing means disposed between said shoulders, and resilient means disposed inside said passage for pressing the plug shoulder against said sealing means.

'2. A clean-out block assembly for use in a furnace wall, comprising a block provided with a passage therethrough in which there is an 'outwardly facing shoulder, a plug disposed in said passage and provided with a surface facing said shoulder, the wall of said passage near its outer end being provided with a pair of oppositely disposed recesses extending inwardly from the outer end of the passage, aid wall also having a pair of oppositely disposed circumferential grooves opening into said recesses, and a spring member extending across said'passage and projecting into said grooves and removable by rotating it until its ends enter said recesses, the central portion of the spring member bearing against the outer end of the plug to urge it inwardly.

3. A clean-out block assembly for use in a furnace wall, comprising a block provided with a cy lindrical passage therethrough in which there is an outwardly facing shoulder, a cylindrical plug disposed in said passage and provided with a surface facing said shoulder, and sealing means pressed against said shoulder by said plug face, the outer end portion of said passage having a recess in its wall extending inwardly of the passage from its outer end, and the outer end portion of said plug having a laterally projecting boss slidable longitudinally in said recess for holding the plug against rotation in the passage.

4. A clean-out block assembly for use in a furnace wall, comprising a block provided with a passage therethrough in which there is an outwardly facing shoulder, a plug disposed in said passage and having an enlarged outer end portion forming an inwardly facing shoulder opposite said passage shoulder, sealing means pressed against said shoulder by said plug face, and heat insulating material carried by the inner end of the plug.

5. In a furnace wall, a block provided with a passage therethrough, a plug disposed in said passage, sealing means compressed against the passage wall by said plug, and another block disposed at the inner end of said first block, the second block being provided with a passage therethrough in axial alignment with said first passage, the second passage flaring gradually outwardly towards its inner end.

HENRY L. SMALLEY. 

